Long division 6 divided by 653

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Can someone me do math because i am having a breakdown rn because i don’t get it

If you double the input of a function and it results in half the output, and if you triple the input and it results in a third of the output, what can be guessed about the function? check all that apply.